Processing aid for paper making

Abstract

Aqueous compositions and process aids useful in paper processing for quenching optical brighteners, particularly under alkaline paper production conditions. The process aids are aqueous compositions comprising (a) an acid addition salt or quartenization product of a cyclic amidine, (b) a polyethyleneimine and optionally (c) an acid. The aqueous compositions and process aids may be added to paper feedstocks in paper production apparatus or to paper production apparatus absent a paper feedstock.

I claim: 
     
       1. An aqueous composition comprising: constituents (a) and (b) wherein constituent (a) is     (i): an acid addition salt or quartenization product of a cyclic amidine of Formula A.1 ##STR14## wherein: Y is an alkylene chain having 2 to 4 carbon atoms,   R 1  is hydrogen, or an alkyl, aryl and aralkyl group where such alkyl, aryl and aralkyl groups contain up to 7 carbon atoms,   X is hydrogen, or a radical of Formula A.2: ##STR15## wherein R 1  and Y are as above defined, or constituent (a) may be: ii): an acid addition salt or quartenization product of a polycondensation product containing two or more units which correspond to the compound of Formula A.3: ##STR16## wherein Y is as defined above, R 2  is an alkylene chain with up to 8 carbon atoms and X 1  is selected from the group consisting of: ##STR17## wherein Y is as above defined and, constituent (b)which is a polyethyleneimine polymer or salt thereof, wherein the weight ratio of constituent (a):constituent (b) is in the range of from 10:1 to 1:3.   
     
     
       2. An aqueous composition according to claim 2 wherein: constituent (a) is as defined in Formula A.3 wherein X 1  is ##STR18## and wherein Y is ethylene. 
     
     
       3. An aqueous composition according to claim 1 wherein constituent (b) is a polyethyleneimine polymer having the general structure according to Formula B.1: ##STR19## wherein x is 100-1,000,000, and each R is independently hydrogen or a structure according to the Formula B.2: ##STR20## wherein y is 1-1,000,000 and each R is independently as above defined. 
     
     
       4. The aqueous composition according to claim 3 wherein the (b) polyethyleneimine polymer has a value of x in the range 250-250,000. 
     
     
       5. The aqueous composition according to claim 1 where the weight ratio of constituent (a):constituent (b) is in the range of from 8:1 to 1:2. 
     
     
       6. The aqueous composition according to claim 5 where the weight ratio of constituent (a): constituent (b) is in the range of from 6:1 to 1:1.5. 
     
     
       7. The aqueous composition according to claim 6 where the weight ratio of constituent (a): constituent (b) is in the range of from 5:1 to 1:1. 
     
     
       8. A process aid preparation for the quenching of fluorescent brighteners which comprises: an aqueous mixture of constituents (a), (b) and (c); wherein constituent (a) is   (i): an acid addition salt or quartenization product of a cyclic amidine of Formula A.1 ##STR21## wherein: Y is an alkylene chain having 2 to 4 carbon atoms,   R l  is hydrogen, or an alkyl, aryl and aralkyl group where such alkyl, aryl and aralkyl groups contain up to 7 carbon atoms,   X is hydrogen, or a radical of Formula A.2: ##STR22## wherein R 1  and Y are as above defined, or, ii): an acid addition salt or quartenization product of a polycondensation product containing two or more units which correspond to the compound of Formula A.3: ##STR23## wherein Y is as defined above, R 2  is an alkylene chain with up to 8 carbon atoms and X 1  is selected from the group consisting of: ##STR24## wherein Y is as above defined, constituent (b) is a polyethyleneimine polymer or a cationic, anionic, or amphoteric salt thereof where the polyethyleneimine polymer has the general structure according to Formula B.1: ##STR25## wherein x is 100-1,000,000, and each R is independently hydrogen or a structure according to the Formula B.2: ##STR26## wherein y is 1-1,000,000 and each R is independently as above defined, and constituent (c) is an organic or inorganic acid, wherein constituent (c) is present in an amount sufficient to form a solution of components (a) and (b) in water.     
     
     
       9. A process aid preparation according to claim 8 wherein constituents (a) and (b) are present in the process aid preparations in the range of from 1% to 85% by weight. 
     
     
       10. A process aid preparation according to claim 9 wherein: constituent (a) is as defined in Formula A.3 wherein X 1  is ##STR27## and wherein Y is ethylene. 
     
     
       11. A process aid preparation according to claim 9 wherein the weight ratio of constituent (a):constituent (b) is in the range of from 10:1 to 1:3. 
     
     
       12. A process aid preparation according to claim 11 wherein the weight ratio of constituent (a):constituent (b) is in the range of from 8:1 to 1:2. 
     
     
       13. A process aid preparation according to claim 12 wherein the weight ratio of constituent (a):constituent (b) is in the range of from 6:1 to 1:1.5. 
     
     
       14. A process aid preparation according to claim 13 wherein the weight ratio of constituent (a):constituent (b) is 3:1. 
     
     
       15. A process aid preparation according to claim 13 wherein the weight ratio of constituent (a) : constituent (b) is in the range of from 2: 1. 
     
     
       16. A process aid preparation according to claim 8 wherein the process aid preparation has a pH in the range of from 2 to 10. 
     
     
       17. A process aid preparation according to claim 16 wherein the process aid preparation has a pH in the range of from 3 to 8. 
     
     
       18. A process aid preparation according to claim 17 wherein the process aid preparation has a pH in the range of from 4 to 61/2. 
     
     
       19. A process for the quenching of fluorescent brighteners in an aqueous paper feedstock which comprises the process step of: co-adding to an aqueous paper feedstock containing at least one optical brightener a component (a) which is   (i):an acid addition salt or quartenization product of a cyclic amidine of Formula A.1 ##STR28## wherein: Y is an alkylene chain having 2 to 4 carbon atoms,   R 1  is hydrogen, or an alkyl, aryl and aralkyl group where such alkyl, aryl and aralkyl groups contain up to 7 carbon atoms,   X is hydrogen, or a radical of Formula A.2: ##STR29## wherein R 1  and Y are as above defined, or constituent (a) may be: ii):an acid addition salt or quartenization product of a polycondensation product containing two or more units which correspond to the compound of Formula A3: ##STR30## wherein Y is as defined above, R 2  is an alkylene chain with up to 8 carbon atoms and X 1  is selected from the group consisting of: ##STR31## wherein Y is as above defined and, and a component (b) which is a polyethyleneimine polymer or a cationic, anionic, or amphoteric salt thereof where the polyethyleneimine polymer has the general structure according to Formula B.1: ##STR32## wherein x is 100-1,000,000, and each R is independently hydrogen or a structure according to the Formula B.2: ##STR33## wherein y is 1-1,000,000 and each R is independently as above defined, wherein the components (a) and (b) are co-added in amounts such that the weight ratio of component (a):component (b) is in the range of from 10:1 to 1:3.   
     
     
       20. A process according to claim 19 wherein: component (a) is as defined in Formula A.3 wherein X 1  is ##STR34## and wherein Y is ethylene. 
     
     
       21. A process according to claim 19 wherein the components (a) and (b) are co-added in amounts such that the weight ratio of component (a):component (b) is in the range of from 8:1 to 1:2. 
     
     
       22. A process according to claim 19 wherein the components (a) and (b) are co-added in amounts such that the weight ratio of component (a): component (b) is in the range of from 6:1 to 1:1.5. 
     
     
       23. A process according to claim 19 wherein the aqueous paper feedstock has a neutral or alkaline pH prior to the addition of component (a) or component (b). 
     
     
       24. A process for the quenching of fluorescent brighteners in an aqueous paper feedstock which comprises the process step of: contacting the feedstock at a neutral or alkaline pH with an effective quenching amount of a composition according to claim 1.   
     
     
       25. A flushing process for use in conjunction with paper production apparatus for quenching fluorescent brighteners which process comprises the step of introducing a composition according to claim 1 into said paper production apparatus wherein no paper feedstock is present.   
     
     
       26. A flushing process for quenching optical brighteners in a paper production apparatus which comprises the step of: introducing a composition according to claim 8 into said paper production apparatus wherein no paper feedstock is present.